If attribute::UseLastModified is set, the catalog::TimeStamp value is returned in the HTTP response as a Last-Modified HTTP header. The Last-Modified header is always returned for static contents, even if attribute::UseLastModified is not set.
For image and SVG contents, catalog::TimeStamp is also used for catalog-based cache validation (see [attribute::CacheValidationPolicy](../../../../../../is-api/image-catalog/image-serving-api-ref/c-image-catalog-reference/c-attributes-reference/r-cachevalidationpolicy.md#reference-e55e52fd749041718a9af69fa2027b57) ).
Date/time value in Java format. Can be either the integer number of milliseconds since midnight, January 1, 1970 UTC/GMT, or a date/time string value with one of the following formats:
mm / dd / yyyy hh : mm : ss zzz
mm / dd / yyyy hh : mm : ss GMT offset
hh is in the range 0 - 23.
zzz is a three or four character time zone code such as 'GMT' or 'PST'. Account for Daylight Savings Time in the time zone code. For example, 'PST' for Pacific Standard Time, versus 'PDT' for Pacific Daylight Savings Time).
offset is a time zone offset in hours or hours:minutes , relative to GMT. For example, 'PDT' is equivalent to 'GMT -7'.
All elements of string formatted date/time values must be present. If the date/time value is not formatted correctly it is ignored and the modification time of the * catalog *.ini file is used instead.
attribute::TimeStamp if the field is empty or not present.